collaborators

9 papers

cs.LG2026

Rethinking Neural Network Learning Rates: A Stackelberg Perspective

Sihan Zeng, Sujay Bhatt, Sumitra Ganesh

Neural networks are typically trained with a single learning rate across all layers. While recent empirical evidence suggests that assigning layer-specific learning rates can accel…

cs.LG2026

A Hessian-Free Actor-Critic Algorithm for Bi-Level Reinforcement Learning with Applications to LLM Fine-Tuning

Sihan Zeng, Sujay Bhatt, Sumitra Ganesh +1

We study a structured bi-level optimization problem where the upper-level objective is a smooth function and the lower-level problem is policy optimization in a Markov decision pro…

cs.LG2025

Learning in Stackelberg Mean Field Games: A Non-Asymptotic Analysis

Sihan Zeng, Benjamin Patrick Evans, Sujay Bhatt +3

We study policy optimization in Stackelberg mean field games (MFGs), a hierarchical framework for modeling the strategic interaction between a single leader and an infinitely large…

cs.LG2025

Catoni-Style Change Point Detection for Regret Minimization in Non-Stationary Heavy-Tailed Bandits

Gianmarco Genalti, Sujay Bhatt, Nicola Gatti +1

Regret minimization in stochastic non-stationary bandits gained popularity over the last decade, as it can model a broad class of real-world problems, from advertising to recommend…

cs.LG2025

Approximate Equivariance in Reinforcement Learning

Jung Yeon Park, Sujay Bhatt, Sihan Zeng +4

Equivariant neural networks have shown great success in reinforcement learning, improving sample efficiency and generalization when there is symmetry in the task. However, in many…

cs.CL2025

Collab: Controlled Decoding using Mixture of Agents for LLM Alignment

Souradip Chakraborty, Sujay Bhatt, Udari Madhushani Sehwag +7

Alignment of Large Language models (LLMs) is crucial for safe and trustworthy deployment in applications. Reinforcement learning from human feedback (RLHF) has emerged as an effect…